Plug comparators of traditional type comprise a support and protection structure, at least two movable arms with feeler elements passing through respective openings in the support and protection structure, at least one transducer for detecting the position of the movable arms, an electric supply, detection and indication group, and electrical connections between the group and the transducer.
These known comparators have various drawbacks resulting from the possibility of foreign matter, such as grease, dust and chips, accumulating within the plug, after possibly entering into the inside of the comparator through the spaces present between the feeler elements and the surfaces of the respective openings of the support and protection structure. As a result of this, the precision and reproducibility of the measurements or even the very operation itself of the comparator may be jeopardized. It is therefore necessary periodically to take the comparator apart in order to carry out cleaning or repair operations.